This brush with celebrity is common in the corporate-speaking industry, with companies paying between $15,000 and $100,000 just to hear someone famous.

But underneath the hype and bragging rights of having celebrities pump up company laggards, experts warn that the industry has its share of lightweights - speakers who spin syrupy tales that have little staying power.

Larry Straus, a business psychologist from Lawrenceville, N.J., says the juicy stories speakers weave tend to quickly fade from employee's memories. "The effect doesn't last very long," he says. "There's no follow through. Change doesn't happen overnight; change takes place over time."

Even Miami Heat head coach and motivational speaker Pat Riley was quoted in USA Today as saying: "There's no way any speaker can come in for one hour and do anything other than raise some pulse rates."

Katrina Salle can attest to that. A travel agent in Montana, Ms. Salle recalls listening to a motivational speaker a few years ago, but now doesn't even remember what the subject was about.

"It motivated you to work harder and think in a different way," Ms. Salle says. "Then you go back to your own way."

Robert Bacal, author of "The Complete Idiot's Guide to Dealing with Difficult Employees," warns that a poorly chosen speaker can have a detrimental effect. Dr. Bacal says the slick, hyped messages of some speakers like "work hard, try hard" doesn't work with adults. "It hardly works with kids," he says.

Bacal thinks bringing in speakers is sometimes "a quick fix to a set of problems [managers] may not have defined."

Managers also run the risk, he says, of employees too forcefully acting on speakers recommendations and ruining office balance. Bacal remembers a former co-worker who took a speaker's suggestions about assertiveness too far, which "lit a fire under her." But her new "ain't gonna take it" attitude cost her her job.

A poorly chosen speaker, Bacal says, could also increase general cynicism about management if employees feel talked down to, or if the seminar proves to be a waste of time.

Good motivational speakers don't rely on flash, says Bacal. They focus on substantive messages with concrete concepts. "If you rely on the [speaker's] performance, that's what people are going to remember," not the message.

Don't tell that to Peter Vidmar. The 1984 Olympic gold medal gymnast and motivational speaker says entertainment is a big part of his presentation. He hauls his pommel horse to speaking engagements, using it as a visual aid.

Entertainment, or not, Mr. Vidmar says it works. "[Employees] get enough people in their industry telling them to do better," he says. When a motivational speaker talks to them, "they pay more attention because it's a different [person] they're getting it from."

He adds that people have written him letters months after his speeches, thanking him for introducing them to "ROV" (risk, originality, virtuosity) and for relating gymnastics to the workplace. (Don't play catch-up, he says, like the US gymnasts did with the Russians for years.)

Athletes and successful business people are the most common speakers corporate America is after these days.

They want, "anyone who's a winner, because American businesses like winners," says Edward Madden, president of Sterling International, a company that locates and books speakers. "In fact I was looking at [New York Yankees coach] Joe Torre's tape yesterday. He said: 'Six years ago nobody cared about what I thought about anything.' Then he started winning championships."

"Often it's a one-shot deal," says Mr. Madden. But sometimes, to reinforce points, speakers may submit an article to the company newsletter. Mr. Riley has been known to leave messages on company phone systems.

Bovis Lend Lease, a global construction firm, has a retainer with Michael Gelb, a workplace author and motivational speaker.

But Jim D'Agostino, the president of Bovis's Western region, says the company uses Mr. Gelb like a consultant and trainer and doesn't force him on employees. "We learned a long time ago to try not to jam anyone down anyone [else's] throat." says Mr D'Agostino. "That doesn't work.

"You're never going to get 100 percent of people retaining the information for a long time," he says, estimating the message stays with 20 percent of the people for an extended period of time.